ASE HVAC Practice Test: Mastering Heating and Cooling
Systems
What would be the most likely result of a missing AC compressor clutch diode? - correct answer
✔✔Damage to the ECM
Tech A says that the service fittings for R-134a are the same as the service fittings for R-12. Tech B says
the low-side service fitting is a 16mm quick-connect and high-side is 13mm quick-connect. Who is right?
- correct answer ✔✔Neither
An inoperative cable-controlled heater control valve is being diagnosed. The control moves freely, but
the valve does not respond. Tech A says the cable housing clamp may be loose at the panel end. Tech B
says the cable may be rusted in the housing. Who is right? - correct answer ✔✔A only
Tech A says that the scan tool receives data from the vehicle by communicating on the data bus network.
Tech B says that if one of the two data bus wires becomes broken, then the network still communicates
on the remaining good wire but will set a trouble code. Who is right? - correct answer ✔✔Both
The tool in the figure above is used to remove and install which AC component? - correct answer ✔✔The
Orifice tube
Referring to the figure above, the blend door gets jammed in the middle of the travel area. What is the
most likely system fault? - correct answer ✔✔The HVAC air temp could not be regulated.
Which AC related procedure would the above tool be used for? - correct answer ✔✔Testing the
refrigerant for impurities.
Referring to the figure above, what would the HVAC malfunction if the component became restricted? -
correct answer ✔✔Low airflow from the ducts.
Referring to the figure above, the AC compressor clutch will not engage. Tech A says that the AC clutch
relay could be bypassed with a fused jumper to test the load side of the circuit. Tech B says that fuse 17
sends power to the AC compressor clutch relay. Who is right? - correct answer ✔✔A only
Systems
What would be the most likely result of a missing AC compressor clutch diode? - correct answer
✔✔Damage to the ECM
Tech A says that the service fittings for R-134a are the same as the service fittings for R-12. Tech B says
the low-side service fitting is a 16mm quick-connect and high-side is 13mm quick-connect. Who is right?
- correct answer ✔✔Neither
An inoperative cable-controlled heater control valve is being diagnosed. The control moves freely, but
the valve does not respond. Tech A says the cable housing clamp may be loose at the panel end. Tech B
says the cable may be rusted in the housing. Who is right? - correct answer ✔✔A only
Tech A says that the scan tool receives data from the vehicle by communicating on the data bus network.
Tech B says that if one of the two data bus wires becomes broken, then the network still communicates
on the remaining good wire but will set a trouble code. Who is right? - correct answer ✔✔Both
The tool in the figure above is used to remove and install which AC component? - correct answer ✔✔The
Orifice tube
Referring to the figure above, the blend door gets jammed in the middle of the travel area. What is the
most likely system fault? - correct answer ✔✔The HVAC air temp could not be regulated.
Which AC related procedure would the above tool be used for? - correct answer ✔✔Testing the
refrigerant for impurities.
Referring to the figure above, what would the HVAC malfunction if the component became restricted? -
correct answer ✔✔Low airflow from the ducts.
Referring to the figure above, the AC compressor clutch will not engage. Tech A says that the AC clutch
relay could be bypassed with a fused jumper to test the load side of the circuit. Tech B says that fuse 17
sends power to the AC compressor clutch relay. Who is right? - correct answer ✔✔A only
